1. Field of the Invention
The present invention generally relates to a data transmission control method, and more particularly to a method of controlling data transmission, from a terminal to another terminal, through a plurality of data channels in an integrated-services digital network.
2. Discussion of the Background
A basic user-network interface in an integrated-services digital network (ISDN) includes several bearer capabilities that are allocated to users. One of the bearer capabilities is that an ISDN terminal connected to the network, via the basic user-network interface, designates a setting of the data transmission describing how the data is transmitted from the terminal to an ISDN receiving terminal. The setting of the data transmission is, for example, that the data is transmitted by using one of two data channels multiplexed to the basic user-network interface. In accordance with the setting inputted at a sending terminal, the ISDN performs a calling procedure for calling the receiving terminal to which the data is transmitted. When an ISDN terminal has two transmission control parts connected to the two data channels in the ISDN interface, and has a two-channel simultaneous transmission capability, which is achieved by operating the two transmission control parts simultaneously and independently, the data transmission can be performed, between the sending terminal and two other ISDN terminals, by using respectively the two data channels in the basic user-network interface, or between the ISDN terminal and a receiving ISDN terminal having the same capability by using simultaneously the two data channels.
As described above, the ISDN terminal which is connected to the ISDN via the basic user-network interface can freely designate a setting of the data transmission describing how the two data channels are used for the data transmission. Therefore, there is a demand for realization of the effective use of the network resources such as the two data channels in the basic user-network interface of the ISDN, and a desire for achieving various data transmission capabilities.